Coiled anchor for supporting prosthetic heart valve, prosthetic heart valve, and deployment device

ABSTRACT

A coiled anchor is positioned at a mitral valve by extending and deflecting a catheter such that a distal end portion of the catheter has a curved shape that is disposed in a left atrium and a distal end of the catheter is positioned near a commissure of the mitral valve. A ventricular portion of the coiled anchor is advanced from the catheter under the mitral valve at the commissure and into a left ventricle. An atrial portion of the coiled anchor is deployed in the left atrium by retracting the catheter off the atrial portion of the coiled anchor while maintaining the position of the ventricular portion of the coiled anchor in the left ventricle.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/912,971, filed on Mar. 6, 2018, which is a division of U.S.patent application Ser. No. 14/628,020, filed Feb. 20, 2015, which is acontinuation-in-part of International Application PCT/US2014/051095filed Aug. 14, 2014, which claims the benefit of U.S. Provisional PatentApplication Nos. 61/865,657 filed Aug. 14, 2013, 61/942,300 filed Feb.20, 2014, and 61/943,125 filed Feb. 21, 2014, all of which are herebyincorporated by reference in their entirety.

BACKGROUND FIELD

The invention generally relates to medical devices and procedurespertaining to prosthetic heart valves. More specifically, the inventionrelates to replacement of heart valves that may have malformationsand/or dysfunctions. Embodiments of the invention relate to a prostheticheart valve for replacing a mitral valve in the heart, an anchor tofacilitate and maintain a positioning of the prosthetic heart valve inthe native valve, and deployment devices and procedures associated withimplantation of the prosthetic heart valve.

Description of Related Art

Referring first generally to FIGS. 1 and 2 , the mitral valve controlsthe flow of blood between the left atrium and the left ventricle of thehuman heart. After the left atrium receives oxygenated blood from thelungs via the pulmonary veins, the mitral valve permits the flow of theoxygenated blood from the left atrium into the left ventricle. When theleft ventricle contracts, the oxygenated blood held in the leftventricle is delivered through the aortic valve and the aorta to therest of the body. Meanwhile, the mitral valve closes during ventricularcontraction, to prevent the flow of blood back into the left atrium.

When the left ventricle contracts, the blood pressure in the leftventricle increases substantially, and urges the mitral valve closed.Due to the large pressure differential between the left ventricle andthe left atrium during ventricular contraction, a possibility ofprolapse, or eversion of the leaflets of the mitral valve back into theatrium, arises. To prevent this, a series of chordae tendineae connectthe mitral valve to the papillary muscles along opposing walls of theleft ventricle. The chordae tendineae are schematically illustrated inboth the heart cross-section of FIG. 1 and the top view of the mitralvalve in FIG. 2 . Just before and during ventricular contraction, thepapillary muscles also contract and maintain tension in the chordaetendineae, to hold the leaflets of the mitral valve in the closedposition and preventing them from turning inside-out and back into theatrium, thereby also preventing backflow of the oxygenated blood intothe atrium.

A general shape of the mitral valve and its leaflets as seen from theleft atrium is illustrated in FIG. 2 . Complications of the mitral valvecan potentially cause fatal heart failure. One form of valvular heartdisease is mitral valve leak, also known as mitral regurgitation,characterized by the abnormal leaking of blood from the left ventricleback into the left atrium through the mitral valve. In thesecircumstances, it may be desirable to repair the mitral valve or toreplace the functionality of the mitral valve with that of a prostheticheart valve.

To this point, mitral valve repair has been more popular than valvereplacement, where prior research and development has been limited.There are little or no effective commercially available ways to replacea mitral valve through catheter implantation and/or other minimal orless invasive procedures. In contrast, the field of transcatheter aorticvalve replacement has developed and has gained widespread success. Thisdiscrepancy stems from replacement of a mitral valve being moredifficult than aortic valve replacement in many respects, for example,due to the physical structure of the valve and more difficult access tothe valve.

The most prominent obstacle for mitral valve replacement is anchoring orretaining the valve in position, due to the valve being subject to alarge cyclic load. Especially during ventricular contraction, themovement of the heart and the load on the valve may combine to shift ordislodge a prosthetic valve. Also, the movement and rhythmic load canfatigue materials, leading to fractures of the implanted valve. If theorientation of a mitral prosthesis is unintentionally shifted, bloodflow between the left atrium and the left ventricle may be obstructed orotherwise negatively affected. While puncturing the tissue in or aroundthe mitral valve annulus to better anchor an implanted valve is anoption for retaining the placement of the implant, this may potentiallylead to unintended perforation of the heart and patient injury.

Referring back to FIG. 2 , another issue with mitral valve replacementis the size and shape of the native mitral valve. Aortic valves are morecircular in shape than mitral valves. Furthermore, in many cases, theneed for aortic valve replacement arises due to, for example, aorticvalve stenosis, when the aortic valve narrows due to reasons such ascalcification and/or hardening of the aortic valve leaflets. As such,the aortic valve annulus itself generally forms a more stable anchoringsite for a prosthetic valve than a mitral valve annulus, which is quitelarge and non-circular. As such, a circular mitral valve implant that istoo small may cause leaks around the implanted valve (i.e., paravalvularleak) if a good seal is not established around the valve. Meanwhile, acircular valve implant that is too large may stretch out and damage thevalve annulus. The outer shape of a valve implant can also potentiallybe manipulated to better fit the mitral valve annulus, for example,through fabric cuff additions on an outer surface of the implant.However, these additions may restrict valve delivery through a catheterand/or minimally invasive procedures, since the additional fabric may bedifficult to compress and deploy through a catheter.

SUMMARY

Since many valves have been developed for the aortic position, it wouldbe desirable to try to take advantage of these existing valvetechnologies and to utilize the same or similar valves in mitral valvereplacements. It would therefore be useful to create a mitral anchor ordocking station for such preexisting prosthetic valves. An existingvalve developed for the aortic position, perhaps with some modification,could then be implanted in such an anchor or docking station. Somepreviously developed valves may fit well with little or no modification,such as the Edwards Lifesciences Sapien™ valve.

It would therefore be desirable to provide devices and methods that canbe utilized in a variety of implantation approaches to facilitate thedocking or anchoring of such valves. Embodiments of the inventionprovide a stable docking station for retaining a mitral valvereplacement prosthesis. Other devices and methods are provided toimprove the positioning and deployment of such docking stations and/orthe replacement prosthesis therein, for example, during variousnon-invasive or minimally invasive procedures. The devices and methodsmay also serve to prevent or greatly reduce regurgitation or leaking ofblood around the replacement prosthesis, such as leakage through thecommissures of the native mitral valve outside of the prosthesis.

Features of the invention are directed to a docking or anchoring devicethat more effectively anchors a replacement valve prosthesis in themitral valve annulus. Other features of the invention are directed to areplacement valve prosthesis that more effectively interacts with ananchoring device according to embodiments of the invention and withsurrounding portions of the native mitral valve and other portions ofthe heart. Still other features of the invention are directed to dockingor anchoring devices and methods for more effectively deployingdifferent portions of the anchoring devices above and below the nativemitral valve annulus (i.e., deploying separate portions of the anchoringdevices into the left atrium and left ventricle, respectively). Stillother features of the invention are directed to corralling or holdingthe chordae tendineae together during deployment of the docking oranchoring devices, to more easily position the docking or anchoringdevices around the native valve leaflets and the chordae tendineae.

In an embodiment of the invention, a coiled anchor for docking a mitralvalve prosthesis at a native mitral valve of a heart has a first end, asecond end, and a central axis extending between the first and secondends, and defines an inner space coaxial with the central axis. Thecoiled anchor includes a coiled core including a bio-compatible metal ormetal alloy and having a plurality of turns extending around the centralaxis in a first position, and a cover layer around the core, the coverlayer including a bio-compatible material that is less rigid than themetal or metal alloy of the coiled core. The coiled anchor is adjustablefrom the first position to a second position wherein at least one of theplurality of turns is straightened for the coiled anchor to be deliveredthrough a catheter to the native mitral valve, and from the secondposition back to the first position. The coiled anchor is implantable atthe native mitral valve with at least a portion on one side of thenative mitral valve in a left atrium of the heart and at least a portionon an opposite side of the native mitral valve in a left ventricle ofthe heart, to support or hold the mitral valve prosthesis in the innerspace when the coiled anchor is implanted at the native mitral valve

In another embodiment, the coiled anchor can be included in a system forimplanting at a mitral valve, where the system can further include amitral valve prosthesis including an expandable frame and housing aplurality of leaflets for controlling blood flow therethrough, whereinthe frame is expandable from a collapsed first position wherein theframe has a first outer diameter for delivery of the mitral valveprosthesis through a catheter to an expanded second position wherein theframe has a second outer diameter greater than the first outer diameter.When the coiled anchor and the mitral valve prosthesis are unbiased, asmallest inner diameter of the inner space defined by the coil anchorcan be smaller than the second outer diameter of the mitral valveprosthesis.

In another embodiment, a coiled anchor for docking a mitral valveprosthesis at a native mitral valve of a heart has a first end, a secondend, and a central axis extending between the first and second ends, anddefines an inner space coaxial with the central axis. The coiled anchorincludes a first coil having a plurality of turns in a firstcircumferential direction and extending from a first end to a secondend, a second coil having a plurality of turns in a secondcircumferential direction opposite to the first circumferentialdirection and extending from a first end to a second end, and a jointconfigured to hold the first end of the first coil and the first end ofthe second coil together, such that the first and second coils eachextends away from the joint and from one another along the central axis.The coiled anchor has a first position where the respective turns of thefirst coil and the second coil each extends around the central axis. Thecoiled anchor is adjustable from the first position to a second positionwherein at least one of the plurality of turns of the first coil or thesecond coil is straightened for the coiled anchor to be deliveredthrough a catheter to the native mitral valve, and from the secondposition back to the first position. The coiled anchor is implantable atthe native mitral valve with at least a portion of the first coil on oneside of the native mitral valve in a left atrium of the heart, and atleast a portion of the second coil on an opposite side of the nativemitral valve in a left ventricle of the heart, to support or hold themitral valve prosthesis in the inner space when the coiled anchor isimplanted at the native mitral valve.

In another embodiment, a method for delivering a coiled anchor that isconfigured to dock a mitral valve prosthesis at a native mitral valve ofa heart includes positioning a catheter for delivery of the coiledanchor at the native mitral valve, positioning a loop around chordaetendineae, closing the loop to draw the chordae tendineae together,advancing the coiled anchor out of the catheter and around the chordaetendineae, and removing the loop and the catheter.

According to embodiments of the invention, mitral valve replacement canbe realized through a variety of different implantation approaches.Embodiments of the invention thus provide flexibility with differentways and options for implanting a replacement mitral valve.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will become apparentfrom the description of embodiments using the accompanying drawings. Inthe drawings:

FIG. 1 shows a schematic cross-sectional view of a human heart;

FIG. 2 shows a schematic top view of the mitral valve annulus of aheart;

FIGS. 3A to 3E show various views of a coil anchor according to anembodiment of the invention;

FIGS. 4A and 4B are respective images of an uncovered coil and a coveredcoil according to an embodiment of the invention;

FIGS. 5A to 5F show a process of deploying a helical coil anchor via atransapical procedure according to an embodiment of the invention;

FIGS. 6A to 6D show a process of deploying a helical coil anchor via atransseptal procedure according to another embodiment of the invention;

FIGS. 7A and 7B show side cross-sectional views of a helical coil anchordeployed in the mitral position, with and without an implanted valveprosthesis, respectively, according to an embodiment of the invention;

FIGS. 8A and 8B respectively show a perspective schematic view of anexemplary transcatheter valve prosthesis, and a cross-section of aportion of the valve prosthesis, according to an embodiment of theinvention;

FIGS. 9A and 9B respectively show a valve prosthesis held in a helicalcoil according to an embodiment of the invention, and a flaring thatoccurs to a frame of the valve prosthesis according to an embodiment ofthe invention;

FIGS. 10A and 10B are respective images illustrating the flaring effectof a valve prosthesis according to an embodiment of the invention;

FIGS. 11A and 11B are schematic images showing a cuff or protectivelayer added to a valve prosthesis according to other embodiments of theinvention;

FIG. 12 shows a perspective view of a helical coil anchor according toanother embodiment of the invention;

FIGS. 13A and 13B respectively show the helical coil anchor of FIG. 12being deployed at a mitral position, and the helical coil anchor of FIG.12 in its final deployed position; and

FIG. 14 shows a modified deployment system according to anotherembodiment of the invention.

DETAILED DESCRIPTION

A helical anchor according to an embodiment of the invention isconstructed as seen in FIGS. 3A to 3E. FIG. 3A shows a perspective viewof a helical anchor 72, FIG. 3B shows a side view of the anchor 72, andFIG. 3C shows a top view of the anchor 72. The helical anchor 72includes a coil with a plurality of turns extending along a central axisof the anchor. The anchor 72 has a series of lower turns or coils 82 anda series of upper turns or coils 84. The individual turns of the lowercoils 82 are spaced apart from one another by small gaps. Meanwhile, theindividual turns of the upper coils 84 are wound more closely to oneanother. In addition, the turns of the lower coils 82 have a largerradius of curvature than the turns of the upper coils 84, and thereforeform a larger inner annular space. These features will be discussed inmore detail below with respect to implantation of the anchor 72 at anative mitral valve. In other embodiments, the characteristics anddifferences between the lower coils 82 and the upper coils 84 of theanchor 72 can be arranged differently based on, for example, the anatomyof the patient.

As can be seen most clearly in FIG. 3C, the anchor 72 twists or coilsaround a central axis of the anchor 72 to provide a generally circularor cylindrical space therein that can more easily hold and anchor acircular valve prosthesis than can the non-circular shape of the nativemitral valve annulus seen in FIG. 2 . Therefore, as can be seen in FIG.3D, when a helical anchor 72 is positioned about a mitral valve 44, thehelical anchor 72 provides a more solid and structurally stable dockingstation or site for docking or coupling valve prostheses to the nativemitral valve annulus. Passage of a portion of the anchor 72 at acommissure 80 of the mitral valve 44 (as seen in FIG. 3D, the process ofwhich will be discussed in greater detail below) allows for placement ofthe anchor 72 both above and below the mitral valve annulus, for moresecure anchoring of a valve prosthesis therein. In addition, a smallestinner space defined by the coils of the anchor 72 can be undersizedrelative to an expanded diameter of a valve prosthesis, such that aradial pressure is generated between the anchor 72 and the valveprosthesis when the prosthesis is expanded therein.

In one embodiment, a core 180 of the helical coil 72 is constructed ofor includes a shape memory material, such as Nitinol. However, in otherembodiments, the core 180 of the helical coil 72 can be made of orinclude other bio-compatible materials, for example, other alloys, orfor example, metals such as titanium or stainless steel. In someembodiments, the coil can have enlarged and/or rounded ends, forexample, to prevent tips at ends of the coil 72 from damagingsurrounding tissue during deployment. As can best be seen in FIGS. 3A,3B, and 3E, the last of which illustrates a cross-section of a portionof the helical coil 72, the core 180 of the coil 72 is covered orsurrounded by a foam layer 182 and a cloth cover 184. In the embodimentshown, the foam layer 182 is a Biomerix foam layer, for example, a 2millimeter thick layer of polyurethane sheet material, and the clothcover 184 is made of or includes a polyester material. In theillustrated embodiment, the respective ends of the foam layer 182 andcloth cover 184 meet circumferentially around the coil core 180 atsubstantially the same place. However, in other embodiments, the foamlayer 182 and cloth cover 184 are wrapped around the coil core 180 andattached at different circumferential points around the coil core 180.The layers 182, 184 can be attached together to the coil core 180, orcan be attached separately to the coil core 180.

In greater detail, in some embodiments, the fabric or cloth cover 184that covers the helical coil is, for example, a polyethyleneterephthalate (PET) polyester material. The fabric can have a thicknessof 0.008±0.002 inches, and can have density characteristics of, forexample, 2.12±0.18 oz/yd², 40±5 wales/inch, and 90±10 courses/inch. Thefabric layer can further be cut to have a length or width ofapproximately 13+1/−0.5 inches in order to cover substantially an entirelength of the helical coil 72.

In some embodiments, the foam layer 182 can be cut to 19 mm×5 mm, andthe cloth cover 184 can be cut to 19 mm×6 mm. However, other sized cutsof the various layers 182, 184 can also be utilized, depending on forexample, the size of the helical coil, the thickness of the respectivelayers, and the amount of each layer intended for covering the core 180.In some embodiments, the foam layer 182 can be attached to the clothcover 184 using, for example, 22 mm of polytetrafluoroethylene (PTFE)suture with a light straight stitch. The foam layer 182 and/or the clothcover 184 can be folded around the coil core 180 and cross-stitched tothe core 180 using, for example, 45 mm of fiber suture. However, theinvention should not be limited to these attachment properties, andother suture sizes and/or types, or any of various other attachmentmeans or methods for effectively attaching the foam layer 182 and/or thecloth cover 184 to the coil core 180, can also be utilized andimplemented. For example, in some embodiments, the core can be amodified core with through holes, notches, or other features that can belaser cut or otherwise formed along the core. Such features in the corecan be used to interact with sutures, to increase friction, or tootherwise help hold a cover layer or layers against the core and preventor restrict sliding or other relative movement between the cover layerand the core. In some embodiments, the core can also be formed to have anon-circular cross-section to increase a contact area between the coreand the cover layer. For example, a flat wire coil can be used to formthe core. Additionally, various bio-compatible adhesives or othermaterials can be applied between the core and the cover layer in orderto more securely hold a position of the cover layer relative to thecore. In some embodiments, a hydrogel or other material that expandsupon contact with blood can be applied between the core and the coverlayer as a gap filler to create a stronger seal or interference fitbetween the core and the cover layer.

FIG. 4A shows a core of one embodiment of a helical anchor prior toapplying a foam and/or fabric cover thereupon, and FIG. 4B shows acovered helical anchor, with a foam layer and a fabric layer, similarlyas described with respect to FIGS. 3A to 3E. The foam and/or fabriclayers are bio-compatible, and generally serve to promote ingrowth ofthe surrounding tissue around and into the anchor, to further secure theanchor about the mitral valve annulus after the anchor and valve havebeen implanted. While in the above described embodiments, both a foamlayer and a fabric layer are applied onto an alloy core of the helicalanchor, in other embodiments, only a foam layer is applied onto the coreof the anchor, while in still other embodiments, only a fabric layer isapplied onto the anchor core.

According to embodiments of the invention, mitral valve replacement canbe performed in various different manners. In one procedure usingcatheters, an anchoring or docking station as described above and/or aprosthetic valve to be positioned in the anchor (which may initially becompressed or collapsed radially) can be delivered through blood vesselsto the implant site. This can be accomplished, for example, througharteries or veins connected to various chambers of the heart. In oneexemplary embodiment (as will be seen in FIGS. 6A to 6D), a catheter canbe delivered through the inferior vena cava into the right atrium, andthen through a transseptal puncture to reach the left atrium above themitral valve.

In some cases, mitral valve replacement may not be purely performedpercutaneously through remote arteries and/or veins, and a more openprocedure may be necessary. In these cases, for example, practitionerscan make a small chest incision (thoractomy) to gain access to theheart, and then place catheter-based delivery devices and/or theimplants directly into the heart.

Referring now to the embodiment in FIGS. 5A to 5F, a transapicalprocedure for positioning a coiled or helical anchor in the mitralposition of a patient's heart is shown. In this example, the anchor isdelivered to the mitral position from the apex of the heart and throughthe left ventricle. FIG. 5A shows an introducer 2 inserted into the leftventricle 10 of a patient's heart 14 through an incision at the apex 6.To prevent blood leakage through the apex 6, a purse string suture canbe tightened around the introducer 2, or an occluder device can be used,among other options. A guide wire 30 is advanced from the introducer 2through the left ventricle 10, past the papillary muscles 56, 60 and thechordae tendineae 48, and between the anterior and posterior leaflets38, 42 of the native mitral valve 44, such that a portion of the guidewire 30 is positioned in the left atrium 46.

As shown in FIG. 5B, a delivery catheter 64 is then introduced over theguide wire 30 into the left atrium 46. The delivery catheter 64facilitates the later introduction of a coil guide catheter 68, whichhas a pre-formed curved shaped designed to assist in the introduction ofa coiled or helical anchor 72. The coil guide catheter 68 isstraightened for introduction through the delivery catheter 64, whichcan be, in contrast, substantially straight and which can be made of astiffer material than the coil guide catheter 68. Therefore, uponexiting the delivery catheter 64, the distal end of the coil guidecatheter can deflect or revert to its original pre-formed curved shapeto assist with proper introduction and positioning of the helical anchor72. The guide wire 30 can be retracted and removed during the process ofdeploying and positioning the coil guide catheter 68, prior to deliveryof the helical anchor 72.

In other embodiments, the coil guide catheter 68 can be introduced intothe heart as a relatively straight element, and can then be manipulatedto take on the desired curved shape.

As shown in FIG. 5C, in an initial coil delivery position, the deliverycatheter 64 has been removed, and the distal end of the coil guidecatheter 68 is positioned in the left atrium 46, near one of the mitralvalve commissures 80, where the anterior mitral valve leaflet 38 meetsthe posterior mitral leaflet 42 near a perimeter of the mitral valve 44.In other embodiments, the distal end of the coil guide catheter caninstead be positioned in the left ventricle 10 near the mitral valve. InFIG. 5C, the distal tip of the lower coils 82 of the helical anchor 72can be seen extending out of the distal end of the coil guide catheter68, and through the mitral valve back into the left ventricle 10. Thetip of the anchor 72 can have a slight downward turn or bend tofacilitate the initial insertion and advancement of the tip back at acommissure 80 of the mitral valve 44.

The helical anchor 72 is then further advanced by being pushed throughthe coil guide catheter 68. FIG. 5D shows the helical anchor 72 beingadvanced and twisting under or around the leaflets 38, 42 of the mitralvalve 44. The helical anchor 72 is directed to go entirely around theleaflets 38, 42 of the mitral valve 44, as well as the chordae tendineae48. The lower coils 82 of the anchor 72 can therefore be made slightlylarger, to facilitate easier corralling or directing of the anchor 72around the leaflets 38, 42, and the chordae 48 during anchor deployment.Additionally, the turns of the lower coils 82 can be spaced slightlyapart from another, for easier advancement of the coils 82 through thenative valve 44 at the commissure 80. Meanwhile, smaller coils, such asthose of upper coils 84, can help more securely or tightly hold a valveprosthesis.

After the lower coils 82 of the anchor 72 have been placed under themitral valve annulus, as seen in FIG. 5E, the upper coils 84 of anchor72 are then deployed from the coil guide catheter 68. In someembodiments, after the lower coils 82 have been advanced under themitral valve annulus to a desired position, it may not be desirable tofurther push or advance the coil 72, in order to keep or maintain theorientation and positioning of the lower coils 82 in the left ventricle10. Therefore, the upper coils 84 of the anchor 72 can be deployed inthe left atrium 46 by rotating the coil guide catheter 68 backwards (asillustrated by the arrows at the bottom of FIG. 5E), in order to revealand deploy more of the coil anchor 72 from within the catheter 68. Otherembodiments deploy and position the upper coils 82 of the anchor 72 invarious different ways.

After the helical anchor 72 is fully implanted, the coil guide catheter68 is removed, as can be seen in FIG. 5F. While the deployed anchor inFIG. 5F has about three coils positioned above the mitral valve 44 andtwo coils positioned below the mitral valve 44, other embodiments canhave other different arrangements and coil positionings based on thespecific application.

It should also be noted that once a helical anchor 72 is inserted andpositioned as described above, and prior to implantation of a prostheticvalve therein, the native mitral valve 44 can continue to operatesubstantially normally, and the patient can remain stable. Therefore,the procedure can be performed on a beating heart without the need for aheart-lung machine. Furthermore, this allows a practitioner more timeflexibility to implant a valve prosthesis within the anchor 72, withoutthe risk of the patient being in a position of hemodynamic compromise iftoo much time passes between anchor implantation and valve implantation.

FIGS. 6A to 6D show an alternative procedure for positioning a helicalanchor in the mitral position of a patient's heart. In this example, ananchor 330 is delivered to the mitral position through the atrial septumof the heart. In an example procedure, a catheter 332 is introduced intoa patient's venous system by percutaneous puncture or by a smallsurgical cut, for example, at the patient's groin. Alternative accesssites can also be used.

As shown in FIG. 6A, the catheter 332 is advanced up the inferior venacava 212, into the right atrium 210, across the atrial septum 304, andinto the left atrium 46. Then, in FIG. 6B, a coil guide catheter 340 isdeployed from a distal end of the catheter 332 and extends to a positionin the left atrium 46 near a commissure 80 of the mitral valve 44,similarly as seen in the embodiment in FIGS. 5A-5F. The anchor 330 exitsthe tip of the coil guide catheter 340 and is advanced under the mitralvalve 44 at the commissure 80.

After the lower coils of the anchor 330 have been positioned under themitral valve 44 to a desired orientation, the upper coils of the anchor330 can then be deployed from the coil guide catheter 340, for example,by rotating the coil guide catheter 340 in the opposite direction ofadvancement of the anchor 330, as shown in FIG. 6C. After the helicalanchor 330 is implanted and placed in a desired position, the coil guidecatheter 340 is removed, as seen in FIG. 6D.

FIG. 7A shows a side cross-sectional view of a helical anchor 72 thathas been implanted in a mitral position of a patient's heart, and FIG.7B shows a side cross-sectional view of a helical anchor 72 with a valveprosthesis 120 retained therein. Orientations, shapes, and sizedifferentials between the different coils of the anchor 72 other thanthose illustrated may also be employed for various reasons, for example,to cause ends of the anchor 72 to push against the ventricular and/oratrial walls, in order to better hold a position of the helical anchor72.

In FIG. 7B, a valve prosthesis 120 is retained by the helical anchor 72in the mitral position. The valve prosthesis 120 is preferably amodified or unmodified transcatheter heart valve, such as, for example,the Edwards Lifesciences Sapien™ valve. Generally, the valve prosthesis120 will include an expandable frame structure 126 that houses aplurality of valve leaflets 122, 124. The expandable frame 126 can beself-expanding, or can be, for example, balloon expandable, and can beintroduced through the same introducer and/or catheters used tointroduce the anchor 72, or may be introduced through a separatecatheter.

In embodiments of the invention, a collapsed valve prosthesis 120 isfirst positioned in a central passage or inner space defined by theanchor 72, and is then expanded to abut against and dock in the anchor72. In these embodiments, at least a portion of the leaflet tissue 38,42 of the mitral valve 44 is secured or pinned between the anchor 72 andthe valve prosthesis 120 to lock the anchor 72 and valve prosthesis 120in position and prevent them from shifting or dislodging. The tissue ofleaflets 38, 42 also creates a natural seal to prevent blood flowbetween the valve prosthesis 120 and the helical anchor 72. As discussedabove, in some embodiments, a smallest inner diameter defined by thecoils of the anchor 72 is smaller than a diameter of the valveprosthesis 120 after it has been expanded, such that a radial resistanceforce is formed between the anchor 72 and the valve prosthesis 120,which further secures the parts together. Pressure between the anchor 72and the valve prosthesis 120 can occur either above or below the mitralvalve 44, or both. Due to the pressure formed between the anchor 72, thevalve prosthesis 120, and the leaflets 38, 42 therebetween, generally noadditional sutures or attachments between the valve prosthesis 120 andthe anchor 72 or the adjacent heart tissue is needed. Due to thedifferent materials used for the anchor 72 and the prosthesis 120, acircumferential friction force is also generated between parts of theanchor 72 and the prosthesis 120 that contact one another, therebyrestricting uncoiling and expansion of the anchor 72. This interactionwill be discussed in greater detail below, with reference to FIGS. 9Aand 9B.

FIGS. 8A-8B show an embodiment of a prosthetic heart valve for use witha helical anchor as previously described. Preferably, the valveprosthesis used with the helical anchor is, for example, a modified orunmodified transcatheter heart valve, such as the Edwards LifesciencesSapien™ valve. FIG. 8A shows a valve having an expandable framestructure 220 and a plurality of valve leaflets 222. The frame 220 ofthe prosthetic valve can be self-expanding and can be made of, forexample, a shape memory material such as Nitinol, or alternatively, canbe made of a non-shape memory material. In some embodiments, the valveprosthesis is balloon expandable, and is intended for expansion within apreviously positioned helical anchor. The leaflets 222 can be made from,for example, pliable animal tissues such as cow, pig, or horsepericardium or valve tissue, or from any other suitable material.

Attached or integral along a distal or lower end of the frame 220, thevalve prosthesis further includes an annular ring or cuff 224 which ismade of or generally includes materials that are less rigid than thematerials of the frame 220. FIG. 8A only schematically shows a shape ofthe annular cuff 224 for simplicity, without additional attachmentfeatures, while FIG. 8B shows a cross-section of a lower portion of avalve prosthesis that includes additional attachment features, such as asleeve 246 that holds the cuff in place on the frame. In the embodimentshown in FIG. 8B, the annular cuff 224 substantially surrounds at leastthe bottom corners 226 of the expandable stent frame 220 of the valveprosthesis. The annular cuff 224 includes a foam layer 242 surroundingthe bottom corners 226 of the frame 220, a fabric layer 244 covering thefoam layer 242, and an additional cuff retention sleeve or layer 246 forholding the foam layer 242 and the fabric layer 244 in place. One ormore stitches or sutures 248 are made between the sleeve layer 246 andone or more portions of the frame 220 to hold the various portions ofthe cuff 224 in place on the frame 220. In the embodiment of FIGS. 8Aand 8B, stitching 248 is made at two different axial regions along theframe 220. However, in other embodiments, more or less stitching 248 maybe employed as needed to retain the cuff 224 on the frame 220, or anyother suitable retention means may be used to hold the foam layer 242and the fabric layer 244 in place on the frame 220, instead of thesleeve layer 246 and stitching 248. Furthermore, in other embodiments,only the foam layer 242 is utilized without the fabric layer 244, oronly the fabric layer 244 is utilized without a foam layer 242, or aring of any other suitable material can be used to form the annular cuff224. The layer or layers of the annular cuff 224 will generally be madeof one or more bio-compatible materials, and will generally be made of amaterial or materials that are softer or less rigid than the materialsor alloys used in the stent frame 220.

FIG. 9A shows an expanded valve prosthesis 120 anchored in a helicalanchor 72 according to an embodiment of the invention. FIG. 9Bschematically illustrates a tendency of the top and bottom ends of thevalve prosthesis 120 to advantageously flare radially outward (e.g., inthe direction of the arrows) upon deployment of the prosthesis 120 in ahelical anchor 72, due to the frictional and resistive forces betweenthe portions of the prosthesis 120 and the anchor 72 that contact oneanother. As discussed above with respect to the anchor 72 in FIGS. 3A to3E, a core of the coil anchor according to embodiments of the inventionis covered with a foam layer and/or a fabric layer, which each serve topromote ingrowth after implantation of the anchor in the mitralposition. Furthermore, the foam or cloth cover of the anchor 72 canserve to prevent or reduce trauma to the tissue that surrounds and comesinto contact with the anchor 72.

In addition, the foam layer and/or fabric layer further serve to createadditional friction upon contact between the anchor 72 and the frame ofvalve prosthesis 120 anchored therein. In the case of metal-basedanchoring or docking stations that do not further include a foam and/orfabric layer thereupon, the material or materials of the anchoring ordocking station may be similar to or the same as the material ormaterials making up the stent frame of the valve prosthesis. In theseinstances, when the valve prosthesis is expanded in the coil anchor andthe stent frame of the prosthesis begins to contact the coil anchor,there may be minimal or low frictional resistance between the stentframe and the coil anchor. Since the unbiased inner diameter of the coilanchor is generally smaller than the outer diameter of the expandedvalve prosthesis, and due to the general wound structure of the helicalcoil, expansion of the valve prosthesis against the helical coil willurge at least the smallest diameter turns of the coil anchor to stretchradially outward and to partially unwind. This, in turn, can cause aslight dislodging or shifting of the anchor within the mitral valveannulus that may be undesirable and cause less effective functionalityof the implanted valve prosthesis, or in a worst case, may lead to aweaker anchoring of the valve prosthesis in the coil anchor andpotential embolization of the valve prosthesis out of the mitral valveannulus and into the left atrium or the left ventricle.

The foam and/or cloth or fabric covered coil anchor 72 according toembodiments of the invention serve to add friction between the coilanchor 72 and valve prosthesis 120 upon contact between the respectiveparts. Initially, when the valve prosthesis 120 is expanded in the coilanchor 72 during implantation of the replacement valve, the metal ormetal alloy frame 220 of the valve 120 will come into contact with thefoam 182 or fabric 184 layer of the coil anchor 72, and acircumferential frictional force between the contacting surfacesprevents the coil anchor 72 from sliding or unwinding under the radiallyoutward forces applied by the expanding frame 220. Such frictionalforces can be generated, for example, from the difference in materialsbetween the outer surface of the cloth or foam covered coil 72 and themetal or alloy frame 220 of the valve prosthesis 120, from interferencebetween the texturing of the cloth or foam covered coil 72 against themetal or alloy surface or various edges of the expandable stent frame220 of the prosthesis 120, or from an interference or “catching” betweenthe cloth or foam covered coil 72 with the edges, transitions or hinges,and/or stitchings on the outer surface of the frame 220 of theprosthesis 120. In other embodiments, other means or reasons for acircumferential friction or locking between the surfaces of the coilanchor 72 and the valve prosthesis 120 can be utilized or employed, inorder to prevent or reduce circumferential migration or expansion of thehelical coil 72 upon radially outward pressure applied from theexpanding valve prosthesis 120.

According to embodiments of the invention, a helical coil 72 with apredefined opening size can more accurately be selected and implanted ina mitral valve annulus for holding or supporting a valve prosthesistherein. A surgeon or practitioner can more accurately select a coilsize and shape together with a desired valve type and size, and theinteraction between the pieces after implantation will be morepredictable and robust. The valve prosthesis can be retained moresecurely in the coil anchor 72, since there will be a tighter hold orretention force between the anchor and the prosthesis, and since therewill be less expansion, shifting, or migration of the anchor within thenative mitral valve annulus upon expansion of the prosthesis therein.

Furthermore, the characteristics of the cloth or foam covered coilanchor 72 according to embodiments of the invention can also assist ineasier implantation and positioning of the coil anchor 72 itself in themitral valve annulus, prior to delivery of the valve prosthesis. First,due to the additional frictional forces contributing to helping latermaintain the structural integrity and/or general size and shape of thecoil anchor 72 against an expanded valve prosthesis, the core of thecoil can be made to be thinner and/or more flexible, which makes theinitial delivery of the coil anchor 72 through the coil guide catheterand into position in the mitral valve annulus easier. In addition, whilea coil with a smaller diameter inner opening generally holds a valveprosthesis more securely, since undesired expansion of the coil anchor72 by the valve prosthesis is prevented or reduced, the coil anchor 72can also be made slightly larger than comparable coil anchors without afoam/cloth cover layer, and advancement of the anchor 72 around thenative mitral valve leaflets and chordae tendineae during deployment ofthe anchor 72 can be more easily facilitated.

Referring now to FIG. 9B, another advantageous feature of the foamand/or cloth covered coil anchor is schematically illustrated. In FIG.9B, only a portion of a valve prosthesis 120 that has been expanded in acoil anchor has been illustrated, with the coil anchor 72 removed forsimplicity, in order to highlight the effect of the coil anchor on avalve prosthesis 120 implanted therein. As can be seen in FIG. 9B, theframe 220 of the valve prosthesis 120 has ends that have flared radiallyoutwards. The frames 220 of the valve implants 120 used in accordancewith embodiments of the invention generally have a constant expandedwidth or diameter along the length of the implant. As described above, acoil anchor will generally be selected to have an inner opening that hasa diameter that is smaller than the expanded diameter of the valveprosthesis 120. Since the friction between the coil anchor 72 and thevalve prosthesis 120 prevents or reduces uncoiling of the coil anchor,and therefore also prevents widening of the opening defined by the coilanchor, an interference fit is formed between the coil anchor and theportions of the valve prosthesis 120 that it comes into contact with.Generally, the valve prosthesis 120 will be centered or substantiallycentered on the coil anchor 72, where the coil anchor 72 directs aninward or resistive force against a central portion of the valveprosthesis 120, as illustrated by the arrow pointing towards the centerof the prosthesis in FIG. 9B. The central portion of the valveprosthesis 120 will therefore be restricted from expanding to its fullyexpanded size. It should be noted that either the prosthetic valve size,the size of the coil anchor, or both, can be selected so as to accountfor this somewhat less-than-full expansion, to avoid compromising thehemodynamics through the prosthetic valve upon implantation. Meanwhile,the top and bottom ends of the valve prosthesis 120, which may not comeinto contact with the coil anchor 72, will continue to try to expandoutwards towards their fully expanded size, as further illustrated bythe arrows near the ends of the prosthesis in FIG. 9B, creating aflaring at the ends of the implant.

FIG. 10A shows a valve prosthesis according to an embodiment of theinvention that has not been implanted in a foam or cloth covered coilanchor, while FIG. 10B shows the valve prosthesis after it has beenexpanded within a foam or cloth covered coil anchor and with the anchorremoved, exhibiting the flaring or widening at the ends of theprosthesis as discussed above.

The flaring exhibited in the valve prosthesis 120 provides a number ofbenefits. The locking dynamic created between the contacting surfaces ofthe coil anchor and the valve prosthesis, coupled with the flared framegeometry of the prosthesis 120, combine to increase retention of theanchor within the coil anchor and the mitral valve annulus. The flaringand widening of the ends of the valve prosthesis 120 add a dimension tothe ends of the prosthesis that serve to create an additional abutmentand obstacle against dislodging of the valve from the coil anchor andpotential embolization of the valve under elevated pressures within theheart. In preliminary tests, while pulsatile pressures up to 70 mmHG andstatic pressures up to 150 mmHg applied against a valve prosthesisanchored in an uncovered metal coil in separate tests did not dislodgethe prosthetic valve from the coil anchor, the prosthetic valve diddislodge from the uncovered anchor at higher static pressures, forexample, pressures above 290 mmHg. Meanwhile, prosthetic valves thatwere anchored in a covered coil anchor according to embodiments of theinvention were successfully retained in all of the above tests.Therefore, a prosthetic valve can be more effectively retained in a foamand/or cloth covered coil anchor. In addition, flaring of thesub-annular portion of the prosthetic valve (i.e., the portion of thevalve located in the left ventricle) will also more securely pinch orhold the native leaflets of the mitral valve against sub-annularportions of the coil anchor, further improving retention of the implant.

Flaring of the ends of the valve prosthesis 120 will increase contactbetween the prosthesis 120 and the surrounding heart tissue, such as thenative mitral valve leaflets and the chordae tendineae. This couldpotentially lead to damage of the surrounding tissue by sharp edges orcorners on the frame 220 of the valve. Referring back to the valveprosthesis illustrated in FIGS. 8A-9B, the annular cuff 224 is thereforeadded to the sub-annular end of the valve prosthesis 120 to protect thesurrounding tissue of the heart from the flared ends of the frame 220which could potentially dig into, cut, or otherwise damage the tissue.

As seen in the previously described embodiments, the annular cuff 224 isrealized as a continuous annular ring covering at least the corners onone end of the stent frame 220 of the valve prosthesis. Meanwhile, FIGS.11A and 11B illustrate two alternative protective cuff arrangements. InFIG. 11A, an alternative cuff layer 264 traces along the bottom (i.e.,the sub-annular) edge of the stent frame 220 of the valve prosthesis120, in order to provide increased protection of the surrounding tissuefrom the entire bottom edge contour of the stent frame 220. In FIG. 11B,another alternative protective layer 284 is realized by spherical orball-shaped protectors attached to the lowermost corners of the stentframe 220. The protective layer 284 in FIG. 11B, or other similar lowprofile arrangements, may be desirable in some applications since, forexample, a stent frame having a lower profile protective layer will beeasier to collapse and deliver through a catheter or delivery sheath. Inaddition, while various different protective layers are illustrated asbeing added only to a sub-annular end of the valve prosthesis 120 in thedescribed embodiments, it will also be understood that similar cufflayers or other protective layers can be added to other portions of thevalve prosthesis 120 in order to prevent or reduce trauma to otherportions of the surrounding tissue caused by the expansion and/orflaring of the stent frame 220.

The coil anchor 72 described in the previous embodiments is made up ofor includes one helical coil. FIG. 12 shows a perspective view of a coilanchor according to another embodiment of the present invention. In FIG.12 , the coil anchor 400 includes a first coil 402 that is wound in afirst circumferential direction, and a second coil 404 that is wound ina second circumferential direction opposite to the first circumferentialdirection. Therefore, the first and second coils 402, 404 can be alignednext to each other along a longitudinal axis of the coils, and at leasta length of each of the coils 402, 404 nearest to one another can bealigned or pushed up against one another. In this configuration, theadjacent ends of the coils 402, 404 are joined together at a joint 406,which in one example is a crimp joint. In another example, the adjacentends of the coils 402, 404 are bonded or welded together, or are heldtogether in one of various other bio-compatible means, and with orwithout other bio-compatible materials, that integrates the coils 402,404 into one single anchor or docking station. The coils 402, 404 extendand wind from the joint 406 in opposite directions, and the first orupper coil 402 terminates in an upper distal end 408, while the secondor lower coil 404 terminates in a lower distal end 410. The upper coilanchor 402 (or atrial anchor) is so named because the upper coil 402will be positioned in the left atrium, above the mitral valve annulus,once deployed. Similarly, the lower coil anchor 404 (or ventricularanchor) is so named because most of the lower coil 404 will be advancedor fed through the mitral valve at a commissure and will be positionedsub-annularly, below the mitral valve annulus, in the left ventricleonce deployed. In some embodiments, the coil anchor 400 can have a coverlayer or layers similar to the cover layers discussed above with respectto the coil anchor 72. In these embodiments, a core of the coil anchor400 can be covered, for example, by a fabric layer, a foam layer, oranother bio-compatible material, or by a combination of such layers.

The coil anchor 400 can initially be deployed similarly to the coilanchor 72 in previously described embodiments. As seen in FIG. 13A, acoil guide catheter 68 is positioned in the left atrium 46, near amitral valve commissure 80. The coil anchor 400 is advanced and beginsextending out of the distal opening of the coil guide catheter 68, andthe distal end 410 of the lower coil 404 is directed through the valveat the commissure 80 to a sub-annular position in the left ventricle.The coil anchor 400 can be advanced via push-out force or load, can bepulled out, the sheath can be withdrawn, or the anchor 400 can bedelivered from the coil guide catheter 68 using one of various otherknown deployment methods. The lower coil 404 is thereafter positionedsimilarly to the coil anchor 72 in previous embodiments. However, duringdeployment of the lower coil 404, the upper coil 402 simultaneouslyadvances out of the distal end of the coil guide catheter 68, and beginsunwinding in an opposite direction, and upwards into the left atrium.Due to the opposite winding directions of the upper and lower coils 402,404, the central axes of the two coils can remain substantially alignedduring and after deployment of the anchor 400. Furthermore, due to theopposite winding directions, the upper and lower coils 402, 404 willnaturally curl or wind in opposite directions when they exit from thecoil guide catheter 68, and will advance away from one another along acentral axis of the coil anchor 400 during deployment. In this manner,once the lower coil 404 is directed through the valve at the commissure80, since the upper coil 402 will deploy upwards rather than followingthe direction of advancement of the lower coil 404, the upper coil 402will naturally move away from the commissure 80, and will notinadvertently be guided through the valve at the commissure 80.

The coil anchor 400 is advanced until the joint 406 exits the distal endof the coil guide catheter 68. Additional adjustments of the anchor to afinal desired position may further be made by the practitioner after thecoil anchor 400 has exited the catheter 68, as needed. As can be seen inFIG. 13B, the coil anchor 400 is deployed to be arranged similarly tothe coil anchor 72 in previous embodiments. In addition, since the upperand lower coils 402, 404 are deployed and positioned at the same time,and since the coil guide catheter can remain in substantially a sameposition throughout deployment of the coil anchor 400, a latter step ofrotating the coil guide catheter 68 in order to release an upper portionof the anchor into the left atrium is no longer necessary, simplifyingthe anchor implanting procedure.

In some embodiments, the upper and lower coils 402, 404 of the coilanchor 400 can be staggered, where the lower coil 404 is slightly longerthan the upper coil 402. In this manner, the distal end 410 of the lowercoil 404 is configured to exit the distal end of the coil guide catheter68 first, for easier positioning of the distal end 410 through the valveat the commissure 80. After the distal end 410 of the lower coil 404 ispositioned through the valve at the commissure 80, the anchor 400 can befully advanced and positioned without adjustment, or with only minoradjustments, to the position of the coil guide catheter 68. In otherembodiments, the upper and lower coils 402, 404 are substantially thesame length, or the upper coil 402 can be longer than the lower coil404. The relative lengths of the two coils of the coil anchor 400 can beadjusted based on the needs of the patient and the preferences of thepractitioner, among other factors.

As has been seen in previous embodiments, different coil anchors can bedeployed at the mitral position in different manners. In eachembodiment, it is important that the leading end, or distal end, of thesub-annular coil (i.e., the portion of the coil anchor that advancesthrough the mitral valve into the left ventricle) is directed completelyaround the native leaflets of the mitral valve and around the chordaetendineae, in order for the anchor to remain closely positioned to themitral valve annulus. For example, if the distal end of the coil doesnot go completely around the chordae tendineae, and is instead advancedbetween two chordae, the coil may become entangled in the chordae,and/or the sub-annular portion of the coil anchor may be held undertissue where the two chordae meet, and thus be deflected farther awayfrom the valve annulus than desired. Such a scenario can have negativeeffects, such as damage to the coil anchor and/or the chordae tendineaeor the native mitral valve leaflets, or unstable anchoring or poorpositioning of a valve prosthesis that is held in the coil anchor.

FIG. 14 shows a coil anchor deployment system according to an embodimentof the invention. In some embodiments, the deployment system has anarrangement similar to that of previously described embodiments, with anintroducer 2, a delivery catheter 64, and a steering catheter or coilguide catheter 68 through which a helical anchor 72 is delivered. In theembodiment illustrated in FIG. 14 , the introducer 2 is positionedthrough the left ventricle 10, but in other embodiments, the introducer2 and/or other delivery catheters can be positioned through the atrialseptum, or any other access site that is suitable for delivery of ahelical anchor.

In addition to the catheters associated with the delivery of the helicalanchor, a separate catheter 18 can be included in the deployment system,and can also be fed and advanced through the introducer 2 or othersheath or cannula in the deployment system. At a distal end of thecatheter 18, a temporary ring or loop 22 is provided, which is used tocorral, bundle, “lasso,” or otherwise draw the chordae tendineae 48together prior to deployment of the helical anchor 72. The chordaetendineae 48 then occupy a smaller cross-sectional area in the leftventricle 10, which facilitates easier later deployment of the distaltip of the helical anchor 72 around the chordae, and placement of thehelical anchor 72 in the desired or optimal position without any chordalentanglement.

The temporary ring or loop 22 can be, for example, a suture or a guidewire, or any other suitable thread or wire. In some embodiments, theloop 22 is led or guided around the chordae tendineae 48 with forexample, a grasping tool or one or more other tools introduced throughthe introducer 2 or through another delivery sheath or cannula. In otherembodiments, the loop 22 is advanced through one or more segmentedguiding catheters around the chordae tendineae 48. In these embodiments,the loop 22 is closed, for example, by utilizing a clamping tool or agrasping tool, via tying, or by one of various other attachment methods,and then the segments of the guiding catheter or catheters areretracted, leaving the loop 22 in its final position around the chordae.In yet other embodiments, the loop 22, like the helical anchor 72, ispre-formed to have a curvature, such that the loop 22 surrounds thechordae tendineae as it is deployed. In some embodiments, after the loop22 has been closed, an opening defined by the loop 22 can further betightened or narrowed, to further bundle or corral the chordae tendineae48 closer together. Meanwhile, while FIG. 14 shows the catheter 18 andloop 22 deployed together with the delivery catheter 64 and the coilguide catheter 68, in other embodiments, any combination of catheterscan be present when the loop 22 is deployed around the chordae tendineae48. For example, in previously described embodiments, the deliverycatheter 64 is retracted before the coil anchor 72 is deployed, and asimilar process can be followed here. Furthermore, in embodiments wherethe introducer 2 is positioned in an apical access site, the loop 22 canalso loop around the introducer and/or one or more of the delivery orcoil guide catheters. If, instead, a transseptal procedure is performed,a distal end of the loop catheter 18 can instead be advanced through themitral valve from the left atrium into the left ventricle, and the loop22 can be deployed around the chordae tendineae 48, without alsobundling or corralling any additional delivery catheters or tubestherein.

After the loop 22 is deployed around the chordae tendineae 48 andbundles or otherwise draws the chordae together, and after the helicalcoil anchor 72 is deployed fully around the chordae and issatisfactorily docked in the mitral position, the loop 22 is removed.This can be accomplished, for example, by a release of the grasping toolif one is utilized, and/or by untying or cutting the suture, thread, orguide wire used for the loop 22, and then removing the loop togetherwith the other tools and catheters in the deployment system from theaccess site.

In embodiments where a loop as described above is utilized in a coilanchor deployment system, issues arising from a coil anchor beingentangled in the chordae tendineae during deployment, or from a coilanchor being stuck between two or more chordae and being positionedincorrectly, can be mitigated or prevented. In this manner, the anchorcan be more securely positioned, and a valve prosthesis can also be moresecurely deployed and implanted therein.

Various other modifications or alternative configurations can be made tothe helical anchors, valve prostheses, and/or deployment systemsaccording to the above described embodiments of the invention. Forexample, in the illustrated embodiments, the coils of the helicalanchors are tightly wound near the mitral valve annulus. In otherembodiments, some of the coils of the anchor may be widened or flaredoutwards to make contact with, for example, the atrial wall of the leftatrium. Furthermore, the number of coils both above and below the valveannulus can be varied, based on for example, properties of the nativemitral valve and/or desired positioning of the valve prosthesis. Inembodiments where upper and lower coils are joined together to form thehelical anchor, the two coils can be prepared, modified, and/or selectedseparately based on a patient's anatomy or various other factors. Inaddition, other modifications to the deployment system can be employedin order to more efficiently or effectively bundle the chordae tendineaeduring deployment and positioning of the helical anchor. Various othercoil shapes, lengths, and arrangements and modifications can also bemade based on a wide range of considerations.

For purposes of this description, certain aspects, advantages, and novelfeatures of the embodiments of this disclosure are described herein. Thedisclosed methods, apparatus, and systems should not be construed asbeing limiting in any way. Instead, the present disclosure is directedtoward all novel and nonobvious features and aspects of the variousdisclosed embodiments, alone and in various combinations andsub-combinations with one another. The methods, apparatus, and systemsare not limited to any specific aspect or feature or combinationthereof, nor do the disclosed embodiments require that any one or morespecific advantages be present or problems be solved.

Although the operations of some of the disclosed embodiments aredescribed in a particular, sequential order for convenient presentation,it should be understood that this manner of description encompassesrearrangement, unless a particular ordering is required by specificlanguage set forth below. For example, operations described sequentiallymay in some cases be rearranged or performed concurrently. Moreover, forthe sake of simplicity, the attached figures may not show the variousways in which the disclosed methods can be used in conjunction withother methods. Additionally, the description sometimes uses terms like“provide” or “achieve” to describe the disclosed methods. These termsare high-level abstractions of the actual operations that are performed.The actual operations that correspond to these terms may vary dependingon the particular implementation and are readily discernible by one ofordinary skill in the art.

In view of the many possible embodiments to which the principles of thedisclosure may be applied, it should be recognized that the illustratedembodiments are only preferred examples and should not be taken aslimiting the scope of the disclosure. Rather, the scope of thedisclosure is defined by the following claims.

What is claimed is:
 1. A method of positioning a coiled anchor at amitral valve comprising: extending and deflecting a catheter such that adistal end portion of the catheter has a curved shape that is disposedin a left atrium and a distal end of the catheter is positioned near acommissure of the mitral valve; advancing a ventricular portion of thecoiled anchor from the catheter under the mitral valve at the commissureand into a left ventricle; deploying an atrial portion of the coiledanchor in the left atrium by retracting the catheter off the atrialportion of the coiled anchor while maintaining the position of theventricular portion of the coiled anchor in the left ventricle; forminga gap between the atrial portion and the ventricular portion to preventtrapping of tissue between the ventricular portion and the atrialportion” after “portion of the coiled anchor in the left ventricle. 2.The method of claim 1 wherein the catheter is advanced along an inferiorvena cava, into a right atrium, across an atrial septum, and into theleft atrium.
 3. The method of claim 1 wherein a distal end of theventricular portion has a downward turn to facilitate the initialinsertion of the ventricular portion into the commissure.
 4. The methodof claim 1 wherein the ventricular portion of the anchor includes aplurality of coils that surround leaflets of the mitral valve.
 5. Themethod of claim 1 wherein the coiled anchor is positioned on the mitralvalve while the heart is beating.
 6. The method of claim 1 wherein anon-parallel coil portion connects the ventricular portion to the atrialportion, such that a gap is formed between the ventricular portion andthe atrial portion.
 7. The method of claim 1 wherein the coiled anchorcomprises a metal core and a plastic coating on the metal core.
 8. Themethod of claim 7 further comprising a suture that extends through ahole in the metal core and the coating.
 9. The method of claim 1 whereinthe coiled anchor comprises a metal core and a plastic coating on themetal core, and a fabric cover on the plastic coating.
 10. The method ofclaim 1 wherein the coiled anchor comprises a metal core having an endportion with a polymer covering, wherein the coiled anchor furthercomprises a fabric covering that only partially covers the polymercovering.
 11. A method of implanting an expansible heart valveprosthesis in the heart of a patient, comprising: extending anddeflecting a catheter such that a distal end portion of the catheter hasa curved shape that is disposed in an atrium of the heart and a distalend of the catheter is positioned near a commissure of a heart valve;advancing a ventricular portion of a coiled anchor from the catheterunder the heart valve at the commissure and into a ventricle; deployingan atrial portion of the coiled anchor in the atrium by retracting thecatheter off the atrial portion of the coiled anchor while maintainingthe position of the ventricular portion of the coiled anchor in theventricle; positioning the expansible heart valve prosthesis within thecoiled anchor with the expansible heart valve prosthesis in anunexpanded state; and expanding the expansible heart valve prosthesisinside the coiled anchor to secure the expansible heart valve prosthesisrelative to the coiled anchor; wherein the heart is a mitral valve;wherein the ventricular portion of the coiled anchor includes aplurality of coils that surround leaflets of the mitral valve; andforming a gap between the atrial portion and the ventricular portion toprevent trapping of tissue between the ventricular portion and theatrial portion” after “expansible heart valve prosthesis relative to thecoiled anchor.
 12. The method of claim 11 wherein the catheter isadvanced along the inferior vena cava, into the right atrium, across theatrial septum, and into the left atrium.
 13. The method of claim 11wherein the coiled anchor comprises a metal core and a plastic coatingon the metal core.
 14. The method of claim 13 further comprising asuture that extends through a hole in the metal core and the coating.15. The method of claim 11 wherein the coiled anchor comprises a metalcore and a plastic coating on the metal core, and a fabric cover on theplastic coating.
 16. The method of claim 11 wherein the coiled anchorcomprises a metal core having an end portion with a polymer covering,wherein the coiled anchor further comprises a fabric covering that onlypartially covers the polymer covering.